In livestock farming, loose houses are used with dunging passages and lying boxes for keeping cows. A lying box is a more or less screened-off space where a cow can lie down to ruminate and rest without being disturbed by other cows walking around in the shed. For milk production, it is important that a cow passes a large part of the day (approximately 10-14 hours a day) lying down. It is further important that the lying surface remains free from excrements, so that the cow does not become soiled with excrements and, in particular, the udders remain clean.
In general, such lying boxes have a rectangular lying surface, geared to the minimum dimensions a cow needs in order to lie or stand comfortably. The cow enters and exits the lying box via an entrance at a rear end of the lying box proximal to the dunging passage. As a rule, the bottom of the lying box is raised relative to the dunging passage that passes along the rear ends of the lying boxes, which dunging passage can be equipped with provisions for discharging excrements. The bottom can be formed from, for instance, hard material, a covering of soft material or loose stable litter or straw.
Gates along the two lengths of the lying box, on the one side, screen the lying box off from, for instance, neighbouring lying boxes or other cows and, furthermore, serve for preventing the cow from standing or lying transversely or askew in the lying box so that upon excretion, the bottom of the lying box would be soiled.
The cows that occupy the lying boxes should preferably, on the one side, stand or lie forward in longitudinal direction so far that the hind legs too stand or rest on the bottom of the lying box. On the other side, the cows should not stand so far forward that, upon excretion, the dung ends up on the bottom of the lying box.
To this end, the lying boxes are customarily provided with a shoulder beam at a height above the floor of the lying box positioned such that the forward freedom of movement of the cow is limited in that the shoulders of the cow contact the shoulder beam when the cow attempts to walk too far forwards over the lying box. Furthermore, lying boxes are sometimes each equipped with a further limiting device on the bottom, for preventing the cows from moving too far forward once they have lied down.
A drawback of a shoulder beam is that it regularly occurs that a cow rises to a standing position that is further forward than the shoulder beam allows. The cow then knocks the shoulder beam from below. This often leads to injuries that may be serious, as serious as breaking of the back, especially when a cow panics due to the wedged-in situation. To prevent forceful contact with the shoulder beam, nylon straps are sometimes used along the shoulder beams. However, becoming wedged-in from below between the strap and the floor may still occur and the nylon strap forms an additional obstacle and, because it can bounce along with the cow, a less accurate limitation than a shoulder beam.
The invention relates to a limiting device according to the introductory portion of claim 1, which, as alternative to the shoulder beam, also serves for limiting, in forward direction, the standing position of the cow and the position from which the cow lies down.
Such a limiting device is known from European patent application 0 659 336. According to a first example, the limiting device is designed as a beam with a height of 15 to 25 cm. Through its location relative to the threshold at the rear end of the lying box, the beam is intended to ensure, in cooperation with a head beam at the front, that after a cow has walked into the lying box, it remains behind the limiting device and will, there, drop to its knees and lie down. According to another example, instead of the beam, a tube is provided, running at a distance above the bottom of the lying box.
A drawback of such a limiting device is that it allows a standing cow to much forward freedom of movement, which leads to the accelerated soiling of the lying box, and/or it leaves a cow lying down too limited a length for lying comfortably in the lying box, which leads to shorter lying times.